From Glossary of Meteorology


Any development or strengthening of cyclonic circulation in the atmosphere; the opposite of cyclolysis.

It is applied to the development of cyclonic circulation where previously it did not exist (commonly, the initial appearance of a low or trough) as well as to the intensification of existing cyclonic flow. While cyclogenesis usually occurs together with deepening (a decrease in atmospheric pressure), the two terms should not be used synonymously.
Compare anticyclogenesis.